Valves generally regulate flow of a fluid, such as a liquid or gas, by controllably obstructing a fluid path within a passageway. Valves can be operated by various control mechanisms, such as electronic or pneumatic sensors, fluid pressure, levers, pedals, and by hand. The size and shape of valves vary depending on their intended use and, similarly, may be constructed out of materials that prevent reactivity with the fluid or provide resilience in pressurized systems.